Cancer and its treatment are associated with considerable distress, impaired quality of life, poor mental health, and reduced physical function. This is particularly true for women with breast cancer who receive multimodal treatment over an extended period of time. Many women undergo surgery and chemotherapy, which are often followed by radiotherapy. It is important to develop programs that can help ameliorate the treatment-related morbidity that accumulates over time for women with breast cancer. Furthermore, given the stressful time demands posed by radiotherapy treatment (patients typically receive treatment 5 days per week for 6 weeks) it is crucial that programs be easily incorporated into the treatment schedule. Research suggests that stress-reduction programs tailored to the cancer setting may help patients cope with the acute effects of treatment and improve QOL after treatment. Yoga, an ancient Indian science, incorporates stress-reduction techniques including regulated breathing, visual imagery, meditation, and various gentle stretching postures. Yoga may be particularly useful for women with breast cancer after surgery and while undergoing radiation treatment because of the stress management and relaxation techniques and the gentle stretching that should facilitate recovery. In this feasibility/pilot project, we will pilot-test and examine the feasibility and usefulness of conducting a yoga program with breast cancer patients as an adjuvant to their radiotherapy treatment. Breast cancer patients undergoing radiotherapy treatment will be randomly assigned to a yoga group or an educational support group. Participants in both groups will attend two sessions each week throughout their 6-week radiation therapy treatment schedule. The sessions will be coordinated with the treatment schedule and conducted adjacent to the treatment facility. Measures will be obtained prior to randomization and 1 week and 1 month after the last session. In addition to determining the acceptability and feasibility of the program, this study will also examine the effects of the yoga program on fatigue and sleep disturbances. Secondary indices of adjustment include QOL and mental health. We hypothesize that the yoga program will be feasible and that patients will find the program acceptable and a positive experience. Integrating a yoga program into the treatment regimen for women undergoing radiotherapy will make it relatively easy to participate in the program and we hypothesize that such a program will help facilitate recovery and alleviate the psychological and physical side effects experienced by patients who are currently receiving radiotherapy.